warptwin::Interpolate2D Class Reference

A class for performing simple x-y linear interpolation. More...

#include <Interpolate2D.h>

Public Member Functions
int	setData (const std::vector< double > &xValues, const std::vector< double > &yValues)
	Sets the data for the interpolator.
int	getMinX (double &minX) const
	Returns the minimum x-value from the stored data.
int	getMaxX (double &maxX) const
	Returns the maximum x-value from the stored data.
int	interpolate (double x, double &yInterpolated)
	Performs linear interpolation given an x-value.

Detailed Description

A class for performing simple x-y linear interpolation.

This class allows you to store tabulated x and y values, and then to compute interpolated y values for any x within the bounds of the stored data. The linear interpolation is performed between successive data points.

Methodology:

• Given a set of points (x[i], y[i]) sorted by increasing x.
• To interpolate at a value x', find the interval [x[i], x[i+1]] such that x[i] <= x' <= x[i+1].
• Then compute:

  

Error Handling:

• The class returns integer error codes rather than using exceptions.
  • 0 indicates success
  • Any non-zero integer indicates an error
• If interpolation is requested for x' below the minimum x or above the maximum x, a non-zero error code is returned.

Member Function Documentation

getMaxX()

int warptwin::Interpolate2D::getMaxX

(

double &

maxX

)

const

Returns the maximum x-value from the stored data.

Parameters

[out]

maxX

The maximum x-value will be written here if the function succeeds.

Returns

Integer error code (0 for success, non-zero for error).

This function returns an error if there is no data stored.

getMinX()

int warptwin::Interpolate2D::getMinX

(

double &

minX

)

const

Returns the minimum x-value from the stored data.

Parameters

[out]

minX

The minimum x-value will be written here if the function succeeds.

Returns

Integer error code (0 for success, non-zero for error).

This function returns an error if there is no data stored.

interpolate()

int warptwin::Interpolate2D::interpolate	(	double	x,
		double &	yInterpolated )

Performs linear interpolation given an x-value.

Parameters

[in]	x	The x-value for which to interpolate.
[out]	yInterpolated	The interpolated y-value will be written here if the function succeeds.

Returns

Integer error code (0 for success, non-zero for error).

If x is out of the bounds of the stored table, this function returns a non-zero error code. If there are not enough points to perform interpolation, it returns a non-zero error code as well.

setData()

int warptwin::Interpolate2D::setData	(	const std::vector< double > &	xValues,
		const std::vector< double > &	yValues )

Sets the data for the interpolator.

Parameters

xValues	A vector of x-values (must be sorted in ascending order).
yValues	A vector of y-values corresponding to xValues.

Returns

An integer error code (0 for success, non-zero for error).

This function replaces any previously stored data with the new x and y values. It is required that xValues.size() == yValues.size() and that xValues is sorted in ascending order. If these conditions are not met, a non-zero error code is returned.

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The documentation for this class was generated from the following files:

• /Users/mickey/Documents/Projects/warptwin/cpp/src/utils/Interpolate2D.h
• /Users/mickey/Documents/Projects/warptwin/cpp/src/utils/Interpolate2D.cpp